The perfume industry has a particular interest in derivatives which are capable of prolonging the effect of active ingredients over a certain period of time (such as pro-fragrances), for example in order to overcome the problems encountered when using perfuming ingredients which are too volatile or have a poor substantivity. In particular, the industry is interested by derivatives with an improved olfactive performance. Said improvement can be in time, in intensity or in the effective amount of active compound released. The improvement in intensity or amount of active compound released can also serve to reduce the perception of malodors.
The patent application WO 03/049666 describes a class of compounds capable of prolonging the effect of active ingredients. Amongst these compounds there are mentioned polymers, citing as specific examples a few styrene co-polymers. However, although the performance described in the examples for several monomeric derivatives is quite good, the performance described for the styrene co-polymers is relatively modest. There is therefore still a need to improve the release properties of polymer based ingredients capable of prolonging the effect of active ingredients. Moreover such prior art polymers are based on synthetic monomers such as alkene, malonate or acrylate, while it is known that there is a preference for more nature-friendly (easier to biodegrade) monomers or backbones.
The aim of the present invention is to provide alternative polymer based pro-fragrances, which avoid classical synthetic backbones (such as polyalkyl or polyacrilate structure) and/or provide improved deposition/performance. Such target is quite ambitious since it is known that by increasing the hydrophilicity (i.e. by using amino-acid backbones) of the polymers it strongly decreases the performance of the over pro-fragrance (see D. L. Berthier et al., in Bioconjugate Chem. 2010, vol. 21, pp. 2000-2012).
The invention's co-polymers are believed to have never previously been disclosed or suggested in the prior art, nor their particular performances in the field of perfume release.